Apparatus for cleaning and buffing metal sheets



May 20, 1941. G. R. DENTON 2,242,292

APPARATUS FOR CLEANING AND BUFFlNG METAL SHEETS Filed Sept. 18, 1937 eorge R ckard Den-l-on \NYR NTOQ Patented May 20,1941

APPARATUS FOR CLEANING AND BUFFIN MIETAL SHEETS George Richard Denton, London, England Application September 18, 1937, Serial No.164,443

In Great Britain September 21, 1936 2 Claims.

This invention relates to the cleaning, scrubbing and bufling of metal sheets, for example the removal of .printed matter from surplus sheets of tinplate and its preparation for subsequent printing or decoration by the manufacturers.

For such purposes it is known to immerse the sheets of tinplate or the like in a hot electrolytic bath containing a suitable solution, as a result of which the print or other foreign matter, grease, or dirt is softened and rendered non-adherent to the metal. .The sheets are then in a condition to be passed through apparatus which washes and scrubs them to remove all traces of the print and other foreign matter, dries them, and finally performs a buffing operation to provide scrupulously clean bright metal sheets ready for re-use. It is to such apparatus that the present invention more particularly relates.

In such apparatus the washing, scrubbing and/0r bufiing operations are conveniently performed by or with the aid of cylindrical brush members or bufling cylinders, each adapted to contact the faces of the metal sheets as the latter are fed between it and a suitable rigid surface along which the sheets travel, each brush member or cylinder rotating about a fixed axis transverse to the direction of travel of the sheets and in such a sense that where it contacts the sheet it moves oppositely to the said direction of travel.

The sheets travel towards each brush in a general plane approximately tangential thereto, and there is thus a possibility of the front edge of a sheet being caught up by the oppositely moving periphery of the brush; with a consequent buckling of the sheet and jamming of the apparatus, which possibility it is the object of the present invention to prevent.

With this object in view, according to the invention, .catching of a sheet by an oppositely rotating brush or cylinder is prevented by a transverse gllide blade directed into the angle between the brush or cylinder and the rigid surface supporting the moving sheets, and bearing on suchsurface to hold against it the entering edge ofa 7 sheet, such guide blade being pivotally carried by" bowed arms about a transverse axis lying above the approaching sheet.

There are obviously many alternative ways in a side view of the cleaning or scouringsection of the apparatus (the final bufling section being of a similar nature). In the cleaning section a flat horizontal bedplate I is provided along which the sheets are fed in succession by spaced pairs 2 of feed rollers. Along the bedplate upper and lower sets 3 and 4 of power-driven brushes are provided, each comprising a cylindrical body rotatably mounted about an axis transverse to the direction of travel of the sheets and bearing bristles.v The overall diameter of each brush is about 7 inches. The brush 3 first encountered by the sheets is mounted above the bedplate with its axis spaced from the succeeding lower brush 4 by a distance of about 14 inches. The lowest part of this brush 3 touches the bedplate, when no sheet is present, and just in front of this, a heavy guide blade positioned tangentially to the surface of the brush, is carried by curved arms 6 pivoted about an axis 1 and serves to hold down the leading edge of a sheet as it passes under the brush.

The lower brush 4 next encountered by the sheets is mounted below the bedplate,- and the uppermost part of its curved surface projects through a transverse aperture or slot in the bedplate and bears slightly, when no sheet is being dealt with, against the underside of a fiat guideplate 8 spaced above the bedplate by a distance. somewhat greater than the thickness of a sheet and having a width, in the direction of travel, substantially greater than the said slot. The guide plate 8 is adjustable by screw means indicated at 9, as to its maximum distance from the bedplate I, and an initial guide plate 8a, similarly mount-ed, is positioned in advance of the guide blade 5. v

Thelb'rushes 3 and l are so rotated that the portions of their peripheries which bear during operation against the metal sheet move oppositely to the direction of feed of the latter; hence the two brushes rotate in opposite directions.

It has been found that in practice. in the particular apparatus illustrated, there is no need to provide guideblades 5 in combination with the lower brushes l, as for some reason these are much less liable to catch on the advancing edge of a sheet than are the upper brushes 3. It is believed that the latter and their associated guideblades 5 give the sheets which are fed to them in substantially flat condition, a slight curvature or set with the leading e e upwards, so that the said leading edge presses up naturally against the guide plates 8 when it approaches the lower brushes. Water is delivered continuously to the apparatus through jets ll, sluicing the removed print or other matter into an inclined run-oi! trough or tray (not shown) undenlying this section, and the sheet is finally delivered by an end pair or feed rollers l0, rubber covered to act as squeegees, to a" drying section (not shown) where it is passed by ribbon conveyors through a heated atmosphere.

Vertically-sliding rack bars [2 are provided on opposite sides of the cleaning apparatus for adjusting the height of each brush and the pressure between each pair of feed rollers, the upper ends of each pair of rack bars being coupled by a worm and wheel reduction gear, indicated generally at l3, to a common transverse rotatable shaft l3a by turning which a fineadjustment can be obtained.

The drying section finally delivers the sheets to the first pair of feed rollers of a bufllng or polishing section, which is not specifically illustrated as it corresponds in essentials to the cleaning section, except thatthe feed rollers are cloth covered and the brushes are replaced by bufling cylinders.

It may also be noted that although reference has been made to cleaning print and the like from tinplate, apparatus according to the invention is equally suitable for analogous purposes, for example de-greasing freshly-tinned sheets or the de-scaling (by scratch-brushing) of sheets before tinning.

I claim:

1. Cleaning, scrubbing and buiilng apparatus for metal sheets, comprising in combination a bedplate, means for advancing a sheet along the same, a transverse cylindrical cleaning element disposed adjacent said bedplate, for rotation in opposition to the movement of said sheet, and a transverse guide blade projecting into the angle between the periphery of said cleaning element and said bedplate and bearing on the latter to hold against it the leading edge of said sheet and prevent buckling thereof by said cleaning element, said guide blade being carried by a bowed arm swingable about a transverse axis arranged above the approaching sheet to hold down the leading edge of the same as it passes under said cleaning element.

2. Apparatus, as claimed in claim 1, including a second cylindrical cleaning element situated below said bedplate and contacting the underside of said sheet through an aperture in said bedplate, 

